Matlab spline interpolation 2

how can i write a MATLAB function, that animates the calculation of a cubic spline with 5 sampling points in an interval [0,a]. the program should: 5 points (x,y) in the area [0,a]x[0,b]. the x values should be equidistant in the interval [0,a], the corresponding y- values should be calculated in the interval [0,b] by a random generator. this example i take from mathwork website: x = 0:10; y = sin(x); xx = 0:.25:10; yy = spline(x,y,xx); plot(x,y,'o',xx,yy)<i> i dont know the coding actually. so i just randomly took the example from mathwork.

help me please. thank you :)